What is the approach to diagnosing and treating bipolar 2 disorder?

Diagnosing Bipolar 2 Disorder

Bipolar 2 disorder requires periods of major depression and hypomania (episodes lasting at least 4 days) but no full manic or mixed manic episodes, according to DSM criteria. 1

Diagnostic Criteria for Bipolar 2

• Hypomania is defined as elevated (euphoric) and/or irritable mood, plus at least three symptoms (four if mood is only irritable): grandiosity, decreased need for sleep, increased talking, racing thoughts, distractibility, overactivity, psychomotor agitation, and excessive involvement in risky activities 1
• Hypomania must last at least 4 days and represent a clear change from baseline functioning, but not be severe enough to cause marked impairment in social or occupational functioning or require hospitalization 2, 1
• Unlike bipolar 1, bipolar 2 does not include full manic or mixed episodes 2, 1
• Depression is often the prominent feature that leads patients to seek treatment 1

Diagnostic Approach

• Organize clinical information using a life chart to characterize course of illness, patterns of episodes, severity, and treatment response 3
• Psychiatric assessments should include specific screening questions for bipolar disorder, focusing on distinct periods of mood changes with associated sleep disturbances and psychomotor activation 3
• The Mood Disorder Questionnaire (MDQ) is the most widely used screening tool for bipolar disorder in outpatient settings 4
• Pay special attention to hallmark hypomanic symptoms: grandiosity, psychomotor agitation, and reckless behavior 3

Diagnostic Challenges

• Bipolar 2 is frequently underdiagnosed - while DSM-IV reported a lifetime community prevalence of 0.5%, epidemiological studies suggest a prevalence of around 5% 1
• About half of bipolar patients consult 3 or more professionals before receiving a correct diagnosis, with an average time to first treatment of 10 years 4
• Bipolar 2 depression can be difficult to differentiate from unipolar depression - in depressed outpatients, one in two may have bipolar 2 1, 5
• The most frequent presentation is depression, with more than 1 in 5 primary care patients with depression actually having bipolar disorder 4

Differentiating Features from Other Conditions

• Manic symptoms must be differentiated from symptoms of other common childhood disorders such as ADHD, disruptive behavior disorders, and PTSD 3
• Manic grandiosity and irritability present as marked changes in the individual's mental state, rather than reactions to situations or temperamental traits 3
• Bipolar depression often differs symptomatically from unipolar depression 4
• Bipolar 2 depression is often "mixed depression" with concurrent, usually subsyndromal, hypomanic symptoms 1

Treatment Approach for Bipolar 2

• Hypomania should be treated even if associated with overfunctioning, because depression often soon follows (hypomania-depression cycle) 1
• Hypomania typically responds to mood-stabilizing agents such as lithium and valproate, and second-generation antipsychotics (olanzapine, quetiapine, risperidone, ziprasidone, aripiprazole) 1
• For acute bipolar 2 depression, evidence is limited but naturalistic studies suggest antidepressants may be effective, though they may worsen concurrent intradepression hypomanic symptoms 1
• Lithium is supported by several studies for preventive treatment of both depression and hypomania 1
• Lamotrigine has shown some efficacy in delaying depression recurrences 1

Comprehensive Management

• A multimodal treatment approach combining psychopharmacology with adjunctive psychosocial therapies is indicated 2
• Psychoeducational therapy should provide information about symptoms, course, treatment options, impact on functioning, and heritability 2
• Relapse prevention education should focus on medication compliance, recognition of emergent symptoms, and factors that precipitate relapse (sleep deprivation, substance abuse) 2
• Family-focused therapy and interpersonal/social rhythm therapy have shown benefit in adults with bipolar disorder 2
• Nearly all patients with bipolar disorder suffer from comorbid psychiatric disorders, most frequently anxiety disorders, which should be evaluated and treated 4

Clinical Pitfalls to Avoid

• Failing to screen for bipolar disorder in patients presenting with depression 4
• Misdiagnosing bipolar disorder as unipolar depression, leading to inappropriate treatment with antidepressants alone 1, 5
• Not recognizing that hypomania often increases functioning, making patients less likely to report it as problematic 1
• Overlooking the need for ongoing monitoring of mood symptoms, psychosocial functioning, and suicide risk 6
• Ignoring the high rate of psychiatric and medical comorbidities in bipolar patients 4, 6